Apparatus for conveying powdered materials in pipes



SP- 30, l930- E. LANHOFFER Er AL PPARATUS Fon cmzvtnmle PowDEREDMATERIALS IN lPIPES 2 Sheets-Sheet 1 Find onta 29. 1925 Sept- 30, 1930l, E. LANHoFr-'ER :sT-AL APPRATUS FOR CONVEYING POWDERED MATERIALS INPIPES Filed Oct. 29, A192:5 2 Sheets-Sheet 2 10 mobility.AH

tion underthe influence of the 35 Ais tightly compressed. y

Patented Sept 30, 1.930

,i UNITED STATES PATENT I'oFFlclt y IVAN EMILE LANHOFIFER AND EDMONDLANHOFFEB, OF PARIS, FRANCE, ASSIGNORS,

BY DIRECT AND 'MESNE ASSIGNMENTS, TO FULLER COMPANY, OF CATASAUQUAPENNSYLVANIA, A CORPORATION F PENNSYLVANIA APPARATUS FOB CONVEYINGPOWDERED MATERIALS IN PIPES Application med October 29,- 1925, SerialNo. 65,652, and in France September 24, 1925'.

This invention relatesito a method of and `apparatus for` conveyingpowdered mater1als in ipes.

It is own that dry powdered materials 5 are very diicult to get compact.This is due to the fact that a considerable amount of air is?Aimprisoned betweenrthe constituent grains especially when inely ground;and theI fner these are the greater their- This property has beenutilized to facilitate the discharge of powdered materials from storagereceptacles or silos containing same. ,In fact, all that isnecessary isto inject air near the outlet aperture and such materials will iowalmost as readily as water. l

There have already l been designed apparatus, based on this principle,in which the .2c materials areA propelled by mechanical presi sure, airbeing injected at a given point of the apparatus, situated in front ofthe mechanical pressure means. In such apparatus the material is tightlypressed prior to the admission o'fgthe air; and the sole purpose of theinjection is-to render the material mobile andto vfacilitate itstransportamechanical pressure. 4 l 4 f These apparatus present thegreatinconvenience of requiring a considerable amount of motive power byreason, of the fact that the propulslve member, Worm or other, works ina material which is devoid of air and A large proportion of the powerabsorbed is expended in overcoming the friction of the membersfgn saidcompact material, and

only, a small amount is utilized for the me- 4o chanical propulsion ofthe material rendered mobile the injection of a small quantityv of air.

The. objectlof the present invention is to' remedy these drawbacks andto dispense entirelywith mechanicahpropulsion.

Accordingnto this invention, the method consists in mixing( with thecrude powdered material a suitable quantity of air under pressure; andthen allowing said air" to ex- -50, pand more or less suddenly. Inconsequence,

carrying of` propelume of the material which remains unaltered.

Under these conditions there arrives a moment when the material can nolonger retain, between its grains, the whole of the injected air; sothat, while remaining mobile, it tends to separate from the surplus airand no longer travels at the same rate as the latter. To remedy thisinconvenience, all

that is necessary is to provide a conveyor tube the sectional area ofwhich decreases progressively towards the discharge orifice, that is tosay, in proportion as the air expands. In this manner, contrary to whathappens in the case of mechanical propulsion, the' ma-4 terials will becarried at increasing velocity towards the outlet of the tube,compressed air will be economized, and the distance traversed canbeincrease'd without having to employ a relay. 1

The conveyor tube may be charged with its mixture of air and material atthe dispatching station by any suitable means.` Said charging means maybe continuous in action (if the material retains air well) or thecharging may be effected in successive quantities of air and material(if the material retains air badly).

A charging system of this kind is employed in the apparatus illustratedas an example of the application of the method just 'described. Therecould be no better way of explaining the principle of the first of'these apparatus than by comparing it with a revolver, the conveyor tuberepresenting the barrel, and the charging device the cylinder ofthatweapon. v

In place of a cartridge the powdered material to beconveyed isintroduced into the chamber of the cylinder, and the chamber madesubstantially air tight by the cheeks" material contained in the chamberbefore the; latter arrives in position in line with the .bari rel, thisair will mix with the powder and occupy the whole ofthe space left freebetween the rains thereof.

hen the chamber which has been charged in this manner comes into linewith the tube, said air expands instantaneously and carries the powderedmaterial into the conveyor tube'. Owing to the velocity acquired by thegrains of powdered material, the chamber, unless of excessive lengthwill be completely emptied. The cylinder revolving in front of theintake end of the tube may also be replaced by compartments describing acontinuous or alternating movement in front of said intake end.

In the event ofany back pressure prevailing in the tube, and as thecylinder revolves rapidly, the expansion will leave in the chamber anair pressure that is slightly below the f back pressure in question.This air, under reduced pressure, is not lost, however, but may, as willbe hereinafter described, be utilized for loosening the materialcontained in the storage bin. p

This system of conveying requires air at a slightly higher pressure thanthe systems of conveying by 'mechanical propulsion; but this differenceis insignificant from the point of view of the power absorbed, since thevol' urne of air is measured exactly by the chamber or cell, and thatnot a fraction of it is wasted.

The air pressure should be adjusted so as to discharge the chamber to asuiiicient extent. The back pressurgJ in the conveyor tube will dependon the length of the tube and on the f material conveyed.

The injection of air into the chamber should also be under control. Inthe case of materials which do not readily allow the air to enetrate inbetween their constituent grains, the injection should be effected sometime prior to the discharge, and ma even be continued for part of thetime they ischarge is in progress. The advancement or retardation, inrelation to the discharge may even be modified while the discharge isproceeding. It will also depend on the delivery output and therotational speed of the cylinder.

The accompanying drawings illustrate, diagrammatically, a typicalapparatus arranged on the lines indicated above.

Fig. 1 represents a transverse section of an apparatus of this kind,takenin the plane of l the line I-I of Fig. 2.

Fig. 2 represents a longitudinal section of the same.

' Fig. 3 represents a'transverse section of a modified form of theapparatus.

Fig.v represents another embodiment of the apparatus.

the part of the cylinder, and is mounted in 'the casing B which formsthe base of the'stor- Vage bin S. The conveyor tube into which Fig. 5represents still another embodiment of the apparatus, in which a memberis provided with a movement of translation.

In Figs. l and 2 the vane wheel A plays thecmaterial is to be deliveredis represented at'i.

rThe vanes of the wheel situated at 1, 2 and 3, iill up with thematerial in the storage bin S.n The rotation of the wheel carriesv themsuccessively into the position 4, and then to 5 where the compressed airarriving through the central tube I-I is injected through apertures Oprovided in each cell, and which, at this point, are uncovered by therotatably ady justable valve E.

When the cell reaches position 6 it is charged under full pressure andwill begin to expand as soon as the vane D uncovers the mouth of thedeliyery tube C.

VIn position f1 the celll has discharged the whole of its contents intothe delivery tube and now contains nothing but air under a slightlylower pressure than that prevailing at the intake of the delivery tube.The conditins are the same in position 8; but as soon as the vane D has'moved beyond the edge F and thereby 'opened up communication between thecell 8 and the storage bin, this air will escape into the silo and mixwith the material contained therein, with the result that said materialis rendered fluid and therefore will more quickly fill the cells.

In a second apparatus, which also enables the method described to becarried into effect, instead of the various cells of the distributorbeing charged with the powdered material first, and the compressed airafterwards (the latter being produced by a suitable machine and admittedfrom a special conduit), the cells of this distributor are charged withair and powdered material. This distributor is actuated in such a waythat the cubical capacity of its compartments or cells diminishesbetween the moment when it is charged with material and the moment whenit discharges the samev into the conveyor tube. Consequently, the airTwhich was under about atmospheric pressure at the 'outset will be underahigher pressure when it reaches the intake of the conveyor tube.

" Hence, at that moment, the conditions will be the (same as with thepreceding apparatus, that isl say, the cell will contain a mixture ofpowdered material and .of air, under pressure, whitc'hvwill expand intheconveyor tube.

It should-be noted that the minimum cubical capacity "oiL the cell, thatis, the capacity at the moment i expansion, should be slightl greatervthan 'the volume of the stacked lightly compact, ip owdered material(assumed to contain the smallest amount of air).

In fact, it `should be remembered that the process is based essentiallon the fact that the material itself is not su jected to any mechanicalpressure. It is the air alone that should be compressed and it istherefore necessary that the minimum volume of the cell should beslightly in excess of that of the material in stacked condition.

It is evident that numerous forms of a paratus operating in this mannercould Ee designed. By yway of example an embodiment of this kind isillustrated in Figure 3` which shows a cross section of the ap varatus.Thus, as can be seen from the drawing, the apparatus shown is composedof a stator B, connected to a suitable hopper S. Inside the statorrevolves van eccentrically mounted rotor A, composed of a'hub in whichare adapted to slide a number of blades or plates K, the edges of whichscrape against the inner walls of thestator. 4rlhis is a well known`device employed in rotary compressors or pumps. The conveyor tube Copens opposite a suitable point of the stator, this pointA approximatelycorresponding to the maximum of compression.

The working of `this apparatus will be selfl evident. The materialcontained in the hopper Sis mixed, as has' already been stated, with theresidual air sup lied bythe cells after having discharged t eir contentsinto the conveyor tube. This residual air and powdered material entersthe cell which occupies the position l in a semisaturated statetherefore does not solidly fill the cell, land the cubical capacity ofthis cell diminishes when it reaches the positions 2 and 3. At the endof the period-3 the cell passes in front ot the tube C, and the air,which is now strongly compressed, projects the material into the tubeandv transports it to the outletg ittl d, lthe lcell contains nothingbut the residual air which is returned to the hopper as soon as theblade K has passed theedge F. The form shown in Fig. 4 discloses bladesK, and the hub provided with projections t on which are pivoted at U,the aps T, the movement of which is restricted, in the openingdirection, by suitable stops. These aps are arranged in such a way thatthey do not come in contact with the wall of the stator except in theposition 3. Y

Ars can be seen from Figure 4, the distance between the edge of theblade K and that of the nap T is approximately'equal to the diameter ofthe intake aperture of the conveyor tubeC. Hence, between the momentwhen one of the cells has finished discharging its contents into thetube C, and the moment .when the next cell begins to discharge, there isa dead interval dueto the passage offth'at portion of the cell which iscomprised betweenthe blade K and the Aflap T.; I

This stagnant period prevents the air and' VVmaterial that have beendischargedinto-the In the form shown in Fig. 5 the member is l endowedwith a movement of translation and consists of a conveyor A moving inrelation to a structure B.

The conveyor A is tprovided with pistons v or partitions D which lvideit into successive compartments. At a point in the path of the conveyor,an aperture O discharges compressed air from a supply pipe H. Theconveyor tube C opens a little urtheralong in the same direction.

The materials arrive from the hopper S into a compartment of theconveyor, and then, in proportion as the conveyor travels, compressedair is admitted into said compartment by way of the aperture O, and themixture of compressed air and material escapes into the tube C. Thiswill, be evident from a simple examination of the iigure; and, moreover,the working of the arrangement is similar to that of Fig. 1, except thatthe cellular rotor A is replaced by the" partitioned conveyor A.

An adjustable slide-H1 enables the duration and timing of the admissionof compressed air to be controlled.

The admission of compressed air may be timed in such a way that it takesplace only at the moment where the position of the cell is already inline with the conveyor tube C.

While we have described our invention in connection with conveyingpowdered materials, we wish it understood that the apparatus is alsowell adapted for use in elevating grain and the like.

What we claim is I. An apparatus of the type described' comprising incombination, a casing, conveying means including a series of wallsforming' chambers therebtween and having oppositely disposed openingsand ports for said chambers, a feed hopper associated with said openingsfor admitting the material to the chambers, an angularly movable devicedisposed in said means arranged to coact with said ports forsuccessively supplying a gaseous medium under high pressure to saidchambers, a discharge pipe associated with the said communicate with theopenings as they are brought into register therewith, and a conduitconnected with the discharge pipe for allowing the rapid expansion ofthe materia-ls supplied thereto and for conducting the materials awaytherefrom. Y

' 2; An apparatus of the type described comprising in combination, acasing, conveying means including a series of walls formlil@ Mtl

Ilo

lfeed hopper and arranged in position to ingchambers therebetween andhaving oppositely disposed lopenings and ports for said chambers, a feedhopper associated with said openings for admitting the material to .thechambers, an angular-ly movable device vIt() disposed in saidmeans'arranged tc coact vwith said ports forv successively supplying agaseous medium under high pressure to the chambers, a discharge pipeoppositely disposed to said feed hopper and arranged in position tocommunicate n'with the openings as they are brought'into registertherewith,

e, and a conduit connected with the discharge pipe for allowing therapid'expansion and subsequent progressive reduction in volume of thehigh pressure mixture supplied thereto and for conducting the materialsaway therefrom. v l

3. An apparatus of the type described comprising in combination, acasing, a feed hopper in said casing, a discharge pipe connected withthe casing and oppositely disposed to said feed hopper, a cellularmember in the casing, means for moving said cellular member with respectto said hopper and discharge pipe, an angularly adjustable device in thecellular member adapted to successively supply the cells 0fV saidmovable device with a gaseous medium under pressure, and a conduitconnected,v with the discharge pipe for allowing the rapid expansionofthe materials supplied thereto and for con-` ducting the materialsaway therefrom. p

4. `An apparatus di the type described comprising in combination,acasing, a feed hopper in said casing, a discharge pipe in the casingand opposltely disposed to said feed hopper, a rotatable wheel in thecasing, a plurality of walled chambers formed in said wheel and adaptedto pass before the hopper and discharge pipe successively, a hollow hubfor said wheel, air inlet openings formed in said hub and communicatingwith said chambers, an Aangularly 'adjustable device disposed in saidhub and adapted to register with said openn the chambers wit a gaseousmedium under pressure, and a conduitconnected with the discharge pipefor allowing the rapid eX- pansion of the materials supplied thereto andfor conducting the materials away therefrom.. i

5. An apparatus of the type described comprising in combination, acasing, a feed hopper in said casing, a discharge pipe in the casing andoppositely disposed to said feed hopper, a rotatable wheelin the casing,a plurality of walled chambers formed in said wheel-and adaptedy to passbefore said hopper and discharge pipe successively,' a hollow hub forthe wheel, a plurality of air inlet openings formed in said hub andcommuni- 'eating with said chambers, a hollow adjustable shaft for thehub, an opening in said shaft adapted to register with the openings inthe hub for supplying the chambers with a gaseous medium under pressure,and ai conduit connected with the discharge pipe for allowing the rapidexpansion of the materials in the hub for supplying l tures. L

IVAN EMILE LANHOFFER. EDMOND LAN HOFFER.

